kotlinlang #tornadofx

hmmm.... I believe that. I'll post my file, but I am not using any rest calls right now. I saw that you can use JSON support as a standalone, but I don't know if I interpreted that correctly

edvin

01/21/2018, 3:58 PM

@amanda.hinchman-dominguez The type mismatch happens because

JsonObject.string()

returns a

String?

and your property called

name

is defined as not nullable. You can change to

JsonObject.getString()

etc instead, those will always return (and require) a value, and optionally takes a default value if the json document didn't contain a value for the key you gave it.

amanda.hinchman-dominguez

01/21/2018, 3:58 PM

@amanda.hinchman-dominguez uploaded a file: GridInfo.json

GridInfo.json

edvin

01/21/2018, 3:59 PM

@amanda.hinchman-dominguez What you posted is a JsonArray, not a JsonObject. You can call

jsonArray

if that is what you want, or you can change the structure of the JSON file to actually be a JsonObject, meaning it starts with curlies, not brackets.

amanda.hinchman-dominguez

01/21/2018, 4:00 PM

@edvin oh wow, yeah.... yeah that makes sense

edvin

01/21/2018, 4:00 PM

If you have a JsonArray and want to turn it into an observable list of your domainobject, you can call

.toModel<ModelType>()

on the JsonArray

👍 1

amanda.hinchman-dominguez

01/21/2018, 4:00 PM

@edvin can you do the same for JsonObject.getInt()? For

rows = JsonObject.getInt("rows")

There is no reference for getInt()

edvin

01/21/2018, 4:00 PM

And I think there is a

loadJsonArray

in there

edvin

01/21/2018, 4:01 PM

@amanda.hinchman-dominguez JsonObject indeed has

getInt()

amanda.hinchman-dominguez

01/21/2018, 4:01 PM

I can do that. Does it really matter whether you use an Object or an Array?

amanda.hinchman-dominguez

01/21/2018, 4:02 PM

It's slightly annoying to run into issues this basic and tiny, but at the same time, I'm glad I'm running into them, because it tells me that I need to pay closer attention to the basics

edvin

01/21/2018, 4:03 PM

@amanda.hinchman-dominguez I didn't mean a static function on the JsonObject class, I meant on an instance of JsonObject, .ie

getInt()

in your case, since

this

is the

json

parameter you sent in to the function.

edvin

01/21/2018, 4:04 PM

rows = getInt("rows")

- if "rows" in the json file is an integer that is

amanda.hinchman-dominguez

01/21/2018, 4:04 PM

@edvin okay - the original issue I was having was the fact that I couldn't use

int

the way I used

string

. Does that mean there's an issue with SimpleIntegerProperty()?

edvin

01/21/2018, 4:06 PM

@amanda.hinchman-dominguez There are some quirks with platform types and the way we create the property delegates, but the error message should be clear and tells you to either supply a nullable or non-nullable type. You can also cirumvent that by accessing the property.value instead, for example

rowsProperty.value = int("rows")

, but I recommend you do

rows = getInt("rows")

amanda.hinchman-dominguez

01/21/2018, 4:07 PM

@edvin okay, I think I get that part, but I think the source of my confusion is why there's no issue for

string

when there is one for

int

. Could it be that a

SimpleStringProperty

could never be null when the same is not true for

SimpleIntegerProperty

amanda.hinchman-dominguez

01/21/2018, 4:09 PM

@edvin I guess I'm just trying to understand what the quirks are 😄

edvin

01/21/2018, 4:09 PM

@amanda.hinchman-dominguez Kind of.. at least seen from the Kotlin type system 🙂

amanda.hinchman-dominguez

01/21/2018, 4:10 PM

Okay - that's helpful for me. I'll read into Kotlin's documentation and see if I can construct something that's definite for types. I find that many blockers I have is understanding how to work with nullable/non-nullable types

amanda.hinchman-dominguez

01/21/2018, 4:11 PM

@edvin I tried loadJsonArray, same error comes back

edvin

01/21/2018, 4:12 PM

@amanda.hinchman-dominguez The property delegate generated by

val rows by rowsProperty

is defined as type

Int

from Kotlin, while the

val name by nameProperty

results in a Java String. Since that's a platform type, it allows null, while the Kotlin type Int doesn't accept null.

amanda.hinchman-dominguez

01/21/2018, 4:12 PM

for that JSON and ImageView, you have to wrap your reference source in

javaClass.getResource(url)

edvin

01/21/2018, 4:12 PM

Using Java's Integer in Kotlin is discouraged, while String is OK.. for some reason

edvin

01/21/2018, 4:12 PM

brb

amanda.hinchman-dominguez

01/21/2018, 4:12 PM

I'm guessing for things like datagrid, you have something that does that already as you iterate through a resource with

it

amanda.hinchman-dominguez

01/21/2018, 4:14 PM

no problem! Sunday is for chores, I know I have to get to them. I wonder why Kotlin doesn't like it - I asked in the general thread, but reading documentation in the meantime

amanda.hinchman-dominguez

01/21/2018, 4:18 PM

For anyone else interested, Weehong sent me this article: https://kotlinlang.org/docs/reference/null-safety.html

poohbar

01/21/2018, 4:59 PM

@edvin Type

String

in Kotlin does not allow null, so I am not sure what you mean.

edvin

01/21/2018, 6:25 PM

@poohbar I'm talking about java.lang.String, when used as a type parameter for a Property.

amanda.hinchman-dominguez

01/21/2018, 7:54 PM

Sure, I have an array that I can parse into objects - Should I try to change my json into an object instead to pass them into jsonmodels easier?